JP6866620B2 - Heat ray shielding film and heat ray shielding glass - Google Patents

Description

The present invention relates to a heat ray-shielding film and a heat ray-shielding glass that transmit near-infrared light having a predetermined wavelength while having good visible light transmittance and an excellent heat ray-shielding function.

Various techniques have been proposed so far as a heat ray shielding technique that has good visible light transmittance and reduces the solar radiation transmittance while maintaining transparency. Among them, the heat ray-shielding technology using conductive fine particles, a dispersion of conductive fine particles, and a laminated transparent base material has excellent heat ray-shielding characteristics, low cost, and radio wave transmission as compared with other technologies. Furthermore, there are merits such as high weather resistance.

For example, in Patent Document 1, a transparent resin containing tin oxide fine powder in a dispersed state or a transparent synthetic resin containing tin oxide fine powder in a dispersed state is molded into a sheet or a film, and the transparent synthetic resin group is used. An infrared absorbent synthetic resin molded product laminated on a material has been proposed.

Patent Document 2 states that Sn, Ti, Si, Zn, Zr, Fe, Al, Cr, Co, Ce, In, Ni, Ag, Cu, Pt, Mn, Ta , W, V, Mo, oxides of the metal, nitrides of the metal, sulfides of the metal, dope of Sb and F to the metal, or intermediate layers in which a mixture thereof is dispersed. , A sandwiched laminated glass has been proposed.

Further, in Patent Document 3, the applicant discloses a coating liquid for a selective permeable membrane and a selective permeable membrane in which at least one of titanium nitride fine particles and lanthanum boride fine particles is dispersed.

However, there is a problem that the heat ray-shielding structures such as infrared-absorbing synthetic resin molded products disclosed in Patent Documents 1 to 3 do not have sufficient heat ray-shielding performance when high visible light transmittance is required. There was a point. For example, as an example of specific numerical values of the heat ray shielding performance of the heat ray shielding structure disclosed in Patent Documents 1 to 3, the visible light transmittance calculated based on JIS R 3106 (in the present invention, simply " When the (visible light transmittance) is 70%, the solar radiation transmittance (in the present invention, simply referred to as “solar transmittance”), which is also calculated based on JIS R 3106, may be described. ) Has exceeded 50%.

Therefore, the applicant is an infrared shielding material fine particle dispersion in which the infrared shielding material fine particles are dispersed in the medium, and the infrared shielding material fine particles are the general formula M _x W _{y Oz} (where the element M is H. , He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, One or more elements selected from I, W is tungsten, O is oxygen, and composite tungsten oxide represented by 0.001 ≦ x / y ≦ 1, 2.2 ≦ z / y ≦ 3.0) The composite tungsten oxide fine particles contain one or more fine particles having a hexagonal, square, or cubic crystal structure, and the particle size of the infrared shielding material fine particles is 1 nm or more and 800 nm or less. A heat ray-shielding dispersion characterized by the above is disclosed as Patent Document 4.

As disclosed in Patent Document 4, the general formula M _x W _y O _z in the heat ray shielding dispersion using the composite tungsten oxide particles expressed showed high heat ray-shielding performance, visible light transmittance of 70% The solar transmittance at that time was improved to less than 50%. In particular, the heat ray-shielding fine particle dispersion using at least one selected from specific elements such as Cs, Rb, and Tl as the element M and having a hexagonal crystal structure of composite tungsten oxide fine particles has excellent heat ray-shielding performance. When the visible light transmittance was 70%, the solar radiation transmittance was improved to less than 37%.

Further, Applicants have the general formula _M a WO _c (where, 0.001 ≦ a ≦ 1.0,2.2 ≦ c ≦ 3.0, M element, Cs, Rb, K, Tl , In, Ba, li, Ca, Sr, Fe, indicated by Sn 1 or more elements selected from among), and contains the composite tungsten oxide fine particles having a hexagonal crystal structure, with the general formula _M a WO _c When the powder color of the composite tungsten oxide shown is ^{evaluated by the L *} a ^* b ^* color system, L ^* is 25 to 80, a ^* is -10 to 10, and b ^* is -15 to 15. The ultraviolet / near-infrared light shielding dispersion characterized by the above is disclosed as Document 5.

In Patent Document 5, while having a predetermined visible light transmission by the combined use of the formula M _a WO _c iron oxide particles and the composite tungsten oxide particles expressed by a constant rate of, near-infrared shielding property At the same time, ultraviolet / near-infrared light-shielding dispersions and ultraviolet / near-infrared light-shielding dispersions having ultraviolet-shielding characteristics, excellent design, and low-saturation bronze tones were obtained.

Japanese Unexamined Patent Publication No. 2-136230 Japanese Unexamined Patent Publication No. 8-259279 Japanese Unexamined Patent Publication No. 11-181336 International Publication No. WO2005 / 037932 Japanese Unexamined Patent Publication No. 2008-231164

However, and composite tungsten oxide nanoparticles expressed by the general formula M _x W _y O _z, the heat ray shielding dispersion using the same heat ray shielding film, solar control glass, heat-ray shielding fine particle dispersion and the combined transparent base As a result of expanding the range of use in the market, new challenges have been found.
Its challenge dispersion containing the formula M _x W _y O composite tungsten oxide microparticles that is described in the _z, the composite tungsten oxide fine particles heat-ray shielding film or solar control glass containing, the composite tungsten oxide fine particles When a body or a heat ray-shielding transparent base material is applied to a structure such as a window material, the transmittance of near-infrared light having a wavelength of 700 to 1200 nm is significantly reduced in the light passing through the window material or the like. Is.
Near-infrared light in the wavelength region is almost invisible to the human eye and can be oscillated by a light source such as an inexpensive near-infrared LED. , Widely used for sensors, etc. However, the structure of the window material or the like using the composite tungsten oxide fine particles expressed by the general formula M _x W _y O _z, the heat ray shielding and heat ray-shielding base material, the dispersion and the combined structure such as a transparent substrate Also strongly absorbs near-infrared light in the wavelength region together with heat rays.
As a result, the via the general formula M _x W structure window material or the like using the composite tungsten oxide particles expressed by _y O _z, a heat ray shielding film or solar control glass, dispersion or combined transparent substrate In some cases, communication using near-infrared light, the use of imaging devices, sensors, etc. were restricted.

For example, when a heat ray shielding film using composite tungsten oxide fine particles described in Patent Document 4 is attached to a window of a general house, it comprises an infrared oscillator placed indoors and an infrared receiver placed outdoors. Communication by near-infrared light between the intrusion detectors was interrupted and the device did not operate normally.

Despite the existence of the above problems, structures such as heat ray shielding films and window materials using composite tungsten oxide fine particles, dispersions, and heat ray shielding laminated transparent substrates have a high ability to cut heat rays significantly, and heat rays. Its use has expanded in market areas where shielding is desired. However, when such a structure such as a heat ray shielding film or a window material, a dispersion, or a heat ray shielding laminated transparent base material is used, wireless communication using near infrared light, an imaging device, a sensor, or the like can be used. It was something I couldn't do.

In addition, the general formula M _x W _y O or composite tungsten oxide fine particles expressed by _z, the heat ray shielding dispersion using the same heat ray shielding film, solar control glass, heat-ray shielding fine particle dispersion and the combined transparent substrate Did not sufficiently shield the heat rays having a wavelength of 2100 nm.

For example, when a heat ray-shielding film using composite tungsten oxide fine particles described in Patent Document 4 was attached to a window of a general house, the skin felt a tingling heat indoors.

The present invention has been made under the circumstances described above. Then, the problem to be solved is that when applied to a structure such as a window material, it exhibits heat ray-shielding characteristics and suppresses a tingling sensation on the skin, and at the same time, the structure, the heat ray-shielding film or It is an object of the present invention to provide a heat ray-shielding film and a heat ray-shielding glass that enable the use of a heat ray-shielding glass, a communication device using near-infrared light via the dispersion or a laminated transparent substrate, an imaging device, a sensor, and the like.

The present inventors have conducted various studies in order to solve the above problems.
For example, it is possible to use a communication device, an imaging device, a sensor, etc. that use near infrared light even through a heat ray shielding film, a heat ray shielding glass, a heat ray shielding dispersion, and a heat ray shielding laminated transparent substrate. Therefore, it was considered that the transmittance of near-infrared light in the wavelength region of 800 to 900 nm should be improved. If the transmittance of near-infrared light in the wavelength region is simply improved, the concentration of the composite tungsten oxide fine particles in the film, the concentration of the composite tungsten oxide fine particles in the heat ray shielding film or the heat ray shielding glass, and the heat ray shielding. It was also considered that the concentration in the film of the composite tungsten oxide fine particles in the dispersion or the heat ray shielding laminated transparent base material should be appropriately reduced.
However, when the concentration of the composite tungsten oxide fine particles and the concentration in the film of the composite tungsten oxide fine particles in the heat ray shielding dispersion or the heat ray shielding laminated transparent substrate are reduced, the heat ray absorbing ability with the wavelength region of 1200 to 1800 nm as the bottom. At the same time, the heat ray shielding effect is reduced, and the skin feels tingling.

Here, it is considered that the reason why sunlight gives a tingling sensation to the skin is that the influence of heat rays having a wavelength of 1500 to 2100 nm is large (for example, Yoshikazu Ozeki et al. See .33-99, 13 (1999). This is because the absorbance of human skin is small for near-infrared light with a wavelength of 700 to 1200 nm, but large for heat rays with a wavelength of 1500 to 2100 nm. It is thought that this is the reason.

Based on the above findings, the present inventors have conducted various studies, and as a result, in the process of heat treatment (calcination) for producing the composite tungsten oxide fine particles represented by the _{general formula M x} W _{y, the reduced state.} By controlling the above within a predetermined range, the absorption capacity at a wavelength of 800 to 900 nm is controlled while maintaining the heat ray absorption capacity at the bottom in the wavelength region of 1200 to 1800 nm, and the absorption capacity in the wavelength region of 2100 nm is improved. It was found that tungsten oxide fine particles can be obtained.

However, the composite tungsten oxide fine particles having improved near-infrared light transmittance in the wavelength region of 800 to 900 nm are indicators conventionally used as an evaluation standard of heat ray shielding performance in a dispersion of heat ray shielding fine particles (for example, When evaluated using the solar radiation transmittance with respect to the visible light transmittance evaluated by JIS R 3106, there was concern that it might be inferior to the composite tungsten oxide according to the conventional technique.
Therefore, from this point of view, the composite tungsten oxide fine particles produced by controlling the reduction state during the heat treatment were further investigated.

The composite tungsten oxide fine particles having improved the transmittance of near-infrared light having a wavelength of 800 to 900 nm by controlling the reduction state during the heat treatment described above are the same as the composite tungsten oxide fine particles according to the prior art. In comparison, it was found that the performance as heat ray-shielding fine particles was not inferior.
This is because the composite tungsten oxide fine particles having improved the transmittance of near-infrared light having a wavelength of 800 to 900 nm also have a large transmittance in visible light. Therefore, it is possible to set a higher concentration of the composite tungsten oxide fine particles per unit area. This is because, as a result of this higher concentration setting, the transmission of heat rays having a wavelength of 1500 to 2100 nm can be suppressed.

As a result of the above studies, the present inventors have a composite tungsten oxide fine particle having a heat ray shielding function, and the visible light transmittance when only the light absorption by the composite tungsten oxide fine particle is calculated is 85%. Sometimes, the average value of the transmittance in the wavelength range of 800 to 900 nm is 30% or more and 60% or less, and the average value of the transmittance in the wavelength range of 1200 to 1500 nm is 20% or less, and the wavelength is 2100 nm. The present invention has been completed by coming up with a heat ray shielding film or a heat ray shielding glass characterized by containing heat ray shielding fine particles having a transmittance of 22% or less.

That is, the first invention that solves the above-mentioned problems is
It is a composite tungsten oxide fine particle having a heat ray shielding function, and when the visible light transmittance when only the light absorption by the composite tungsten oxide fine particle is calculated is 85%, the transmittance in the wavelength range of 800 to 900 nm. The average value of is 30% or more and 60% or less, the average value of the transmittance in the wavelength range of 1200 to 1500 nm is 10.4% or more and 20% or less, and the transmittance of the wavelength of 2100 nm is 15.5. A heat ray-shielding film or heat ray-shielding glass comprising % or more and 22% or less of heat ray-shielding fine particles.
The second invention is
A heat ray-shielding film or heat ray-shielding glass characterized in that the composite tungsten oxide fine particles have a hexagonal crystal structure and the lattice constant of the c-axis is 7.56 Å or more and 8.82 Å or less.
The third invention is
A heat ray having a coating layer on at least one surface of a transparent base material selected from a transparent film base material or a transparent glass base material, and the coating layer is a binder resin layer containing the heat ray shielding fine particles. Shielding film or heat ray shielding glass.
The fourth invention is
The binder resin is a heat ray-shielding film or heat ray-shielding glass, characterized in that it is a UV curable resin binder.
The fifth invention is
A heat ray-shielding film or heat ray-shielding glass characterized in that the thickness of the coating layer is 10 μm or less.
The sixth invention is
The transparent film base material is a heat ray shielding film characterized by being a polyester film.
The seventh invention is
A heat ray-shielding film or heat ray-shielding glass in which the content of the heat ray-shielding fine particles contained in the coating layer per unit projected area is 0.1 g / m ² or more and 5.0 g / m ^{2 or less.}
The eighth invention is
It is a heat ray shielding film, and when the visible light transmittance is 70%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 13% or more and 40% or less, and the transmittance is in the wavelength range of 1200 to 1500 nm. Whether the average value of the rate is 3.6% or more and 8% or less and the transmittance at a wavelength of 2100 nm is 5.4% or more and 9% or less.
Alternatively, in the case of heat ray shielding glass, when the visible light transmittance is 70%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 13% or more and 40% or less, and the wavelength is in the range of 1200 to 1500 nm. According to any one of claims 1 to 7, wherein the average value of the transmittance in the above is 2.7% or more and 8% or less, and the transmittance at a wavelength of 2100 nm is 4.5% or more and 9% or less. The heat ray shielding film or heat ray shielding glass described.
The ninth invention is
A mixing step of mixing tungstic acid and a hydroxide powder of one or more elements selected from Cs, Rb, K, Tl, and Ba at a predetermined ratio to obtain a mixed powder.
The mixed powder, the inert gas performs a reduction treatment by heating under H ₂ gas supply from 0.1 to 0.5% of the carrier, one selected Cs, Rb, K, Tl, Ba, A firing process for obtaining a composite tungsten oxide powder containing the above elements,
A step of uniformly mixing the composite tungsten oxide powder into a transparent resin to obtain a heat ray-shielding fine particle dispersion, and
A method for producing a heat ray-shielding film or heat ray-shielding glass, which comprises a step of coating the heat ray-shielding fine particle dispersion on a transparent film base material or a transparent glass base material.
However, the composite tungsten oxide powder has a hexagonal crystal structure, the lattice constant of the c-axis is 7.56 Å or more and 8.82 Å or less, and the powder color is L ^* a ^* b ^* color. In the system, it contains composite tungsten oxide fine particles in which ^{L *} is 30 to 55, a ^* is −6.0 to −0.5, and b ^{* is −10 to −0.}
When the visible light transmittance when only the light absorption by the composite tungsten oxide fine particles is calculated is 85%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 30% or more and 60% or less, and The average value of the transmittance in the wavelength range of 1200 to 1500 nm is 10.4% or more and 20% or less, and the transmittance at the wavelength of 2100 nm is 15.5% or more and 22% or less.
The tenth invention is
Further, the heat ray shielding glass or the heat ray shielding film is characterized by containing one or more kinds selected from an ultraviolet absorber, HALS, and an antioxidant.

The heat ray-shielding film and heat ray-shielding glass according to the present invention exhibit heat ray-shielding characteristics, suppress a tingling sensation on the skin, and use near-infrared light even when these structures or the like intervene. It is possible to use the existing communication equipment, imaging equipment, sensors, etc.

It is a transmittance profile for each wavelength of the heat ray shielding film which concerns on this invention.

Hereinafter, with respect to the embodiment for carrying out the present invention, [a] a method for producing heat ray shielding fine particles preferable for producing a heat ray shielding film and heat ray shielding glass, [b] a method for producing heat ray shielding fine particles preferable for producing a heat ray shielding film and heat ray shielding glass, [ c] A heat ray-shielding fine particle dispersion liquid preferable for producing a heat ray-shielding film and a heat ray-shielding glass, and [d] a method for producing the heat ray-shielding film and the heat ray-shielding glass will be described in this order.

[A] Heat ray shielding fine particles (composite tungsten oxide fine particles) preferable for producing a heat ray shielding film and heat ray shielding glass.
The heat ray-shielding fine particles according to the present invention have an average transmittance of 30% or more and 60% at a wavelength of 800 to 900 nm when the visible light transmittance is 85% when only the light absorption by the composite tungsten oxide fine particles is calculated. These are composite tungsten oxide fine particles having a transmittance of 20% or less in the wavelength range of 1200 to 1500 nm and a transmittance of 22% or less at a wavelength of 2100 nm.
Then, when expressed by the general formula _M x WO _y, element M is one or more kinds of elements selected Cs, Rb, K, Tl, from Ba, W is tungsten, O is oxygen. Then, the composite tungsten oxide fine particles satisfy 0.1 ≦ x ≦ 0.5 and 2.2 ≦ y ≦ 3.0.
Further, it is a composite tungsten oxide fine particle having a hexagonal crystal structure, and is a heat ray shielding fine particle having a c-axis lattice constant of 7.56 Å or more and 8.82 Å or less.

The amount of element M added is preferably 0.18 or more and 0.5 or less, and more preferably 0.18 or more and 0.33 or less. This is because when the value of x is 0.18 or more and 0.33 or less, a hexagonal crystal single phase can be easily obtained and the heat ray absorbing effect is sufficiently exhibited. In addition to hexagonal crystals, tetragonal crystals and _{orthorhombic crystals represented by M 0.36} WO _3.18 (Cs ₄ W ₁₁ O ₃₅ ) may precipitate, but these precipitates do not affect the heat ray absorption effect.

The value of y is preferably 2.2 ≦ y ≦ 3.0, more preferably 2.7 ≦ y ≦ 3.0. Further, in the composite tungsten oxide, a part of oxygen may be replaced with another element. Examples of the other element include nitrogen, sulfur, halogen and the like.

The particle size of the composite tungsten oxide fine particles according to the present invention can be appropriately selected depending on the purpose of use of the composite tungsten oxide fine particles and the heat ray shielding film / heat ray shielding base material produced by using the dispersion liquid. It is preferably 1 nm or more and 800 nm. This is because if the particle size is 800 nm or less, the composite tungsten oxide fine particles according to the present invention can exhibit strong near-infrared absorption, and if the particle size is 1 nm or more, industrial production is easy. Is.

When the heat ray shielding film is used in an application requiring transparency, it is preferable that the composite tungsten oxide fine particles have a dispersed particle size of 40 nm or less. When the composite tungsten oxide fine particles have a dispersed particle size smaller than 40 nm, light scattering due to Mie scattering and Rayleigh scattering of the fine particles is sufficiently suppressed, and visibility in the visible light wavelength region is maintained, and at the same time. This is because the transparency can be efficiently maintained. When used in applications where transparency is particularly required, such as windshields of automobiles, the dispersed particle size of the composite tungsten oxide fine particles is preferably 30 nm or less, preferably 25 nm or less, in order to further suppress scattering.

The composite tungsten oxide fine particles according to the present invention have improved near-infrared light transmittance in the wavelength region of 800 to 900 nm while ensuring the heat ray absorption capacity of the wavelength of 1200 to 1500 nm with the wavelength of 1200 to 1800 nm as the bottom, and the wavelength of the composite tungsten oxide fine particles is improved. It is considered that the reason for ensuring the heat ray absorption capacity of 2100 nm is due to the electronic structure of the composite tungsten oxide fine particles and the light absorption mechanism derived from the electronic structure.

In the composite tungsten oxide microparticles indicated by the general formula M _x WO _y according to the present invention, the element M is one kind selected Cs, Rb, K, Tl, out of one or more elements selected from Ba These elements, W is tungsten and O is oxygen. Then, the composite tungsten oxide fine particles having a hexagonal crystal structure satisfying 0.1 ≦ x ≦ 0.5 and 2.2 ≦ y ≦ 3.0.

The value of x, which is the amount of the element M added, is preferably 0.18 or more and 0.5 or less, and more preferably 0.18 or more and 0.33 or less. This is because when the value of x is 0.18 or more and 0.33 or less, a hexagonal crystal single phase can be easily obtained and the heat ray absorbing effect is sufficiently exhibited. In addition to hexagonal crystals, tetragonal crystals and _{orthorhombic crystals represented by M 0.36} WO _3.18 (Cs ₄ W ₁₁ O ₃₅ ) may precipitate, but these precipitates do not affect the heat ray absorption effect.

(Heat treatment conditions in the production of composite tungsten oxide fine particles)
The present inventors produced composite tungsten oxide fine particles in the same manner as in Example 3 described later, except that the four levels of heat treatment conditions <heat treatment conditions 1 to 4> described below were used.

<Heat treatment condition 1>
After heat-reduction treatment at a temperature of 500 ° C. for 30 minutes under _{a 0.3% H 2} gas supply using N ₂ gas as a carrier, firing was performed at a temperature of 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} ..

<Heat treatment condition 2>
This is the same as the heat treatment according to Example 1 described later.
After heat-reduction treatment at a temperature of 500 ° C. for 4 hours under _{a 0.3% H 2} gas supply using N ₂ gas as a carrier, firing was performed at a temperature of 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} ..

<Heat treatment condition 3>
This is the same as the heat treatment according to Example 3 described later.
After heat-reduction treatment at a temperature of 500 ° C. for 6 hours under _{a 0.3% H 2} gas supply using N ₂ gas as a carrier, firing was performed at a temperature of 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} ..

<Heat treatment condition 4>
This is the same as the heat treatment according to Comparative Example 1 described later.
After heat-reduction treatment at a temperature of 550 ° C. for 1 hour under _{a 5% H 2} gas supply using N ₂ gas as a carrier, firing was performed at a temperature of 800 ° C. for 1 hour under _{an N 2 gas atmosphere.}

Except for using the cesium tungsten bronze produced by applying the four levels of heat treatment conditions of <heat treatment conditions 1 to 4> described above, the same operation as in Example 1 described later was performed to shield the heat rays of the samples 1 to 4. A fine particle dispersion was obtained.

The average dispersed particle size of the composite tungsten oxide fine particles (cesium tungsten bronze fine particles) according to the present invention in each heat ray-shielding fine particle dispersion sample was measured and found to be in the range of 20 to 30 nm.

<Summary of heat treatment conditions 1 to 4>
In the heat treatment for producing the composite tungsten oxide fine particles, the present inventors control the reduction treatment to the weaker side by controlling the temperature condition and the atmospheric condition, and only the light absorption by the composite tungsten oxide particles is performed. When the calculated visible light transmittance is 85%, the average value of the transmittance at a wavelength of 800 to 900 nm is 30% or more and 60% or less, and the average value of the transmittance in the wavelength range of 1200 to 1500 nm is. It was possible to obtain composite tungsten oxide particles having a transmittance of 20% or less and a transmittance of 22% or less at a wavelength of 2100 nm.
The composite tungsten oxide fine particles had a hexagonal crystal structure and had a c-axis lattice constant of 7.56 Å or more and 8.82 Å or less.
Further, since the transmittance of the composite tungsten oxide fine particles increases in the visible light region, the concentration of the composite tungsten oxide fine particles in the heat ray shielding film can be slightly increased.

Then, comparing the shape of the transmittance profile of the composite tungsten oxide particles according to the present invention described above with the transmission profile of the composite tungsten oxide fine particles according to the prior art, the following features (1)-(3) are exhibited. Have.
(1) The composite tungsten oxide particles according to the present invention have a visible light transmitting band region extending to a wavelength region of 800 to 900 nm, which is a region of near infrared light, and have high transmittance even in the wavelength region. It has.
(2) The composite tungsten oxide particles according to the present invention have a substantially constant transmittance value in a wavelength region of 1200 to 1500 nm.
(3) The composite tungsten oxide particles according to the present invention have heat ray shielding performance even at a wavelength of 2100 nm.

[B] Method for producing heat ray-shielding fine particles preferable for producing a heat ray-shielding film and heat-shielding glass The composite tungsten oxide fine particles according to the present invention can be obtained by heat-treating a tungsten compound starting material in a reducing gas atmosphere.

First, the starting material for the tungsten compound will be described.
The starting material for the tungsten compound according to the present invention is a simple substance or a mixture containing a compound of tungsten and element M, respectively. As the tungsten raw material, tungsten acid powder, tungsten trioxide powder, tungsten dioxide powder, tungsten oxide hydrate powder, tungsten hexachloride powder, ammonium tungstate powder, or tungsten hexachloride powder is dissolved in alcohol and then dried. Tungsten oxide hydrate powder obtained in the above, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol, adding water to precipitate, and drying this. , Any one or more selected from tungsten compound powder and metallic tungsten powder obtained by drying an ammonium paratungate aqueous solution is preferable. Examples of the raw material of the element M include element M alone, element M chloride salt, nitrate, sulfate, oxalate, oxide, carbonate, tungstate, hydroxide and the like, but are limited thereto. Not done.

The above-mentioned tungsten compound starting material is weighed, and the mixture is blended and mixed in a predetermined amount satisfying 0.1 ≦ x ≦ 0.5. At this time, it is preferable that the raw materials of tungsten and the element M are uniformly mixed as much as possible, preferably at the molecular level. Therefore, it is most preferable that each of the above-mentioned raw materials is mixed in the form of a solution, and it is preferable that each raw material is soluble in a solvent such as water or an organic solvent.
If each raw material is soluble in a solvent such as water or an organic solvent, the tungsten compound starting material according to the present invention can be produced by sufficiently mixing each raw material and the solvent and then volatilizing the solvent. However, even if each raw material does not have a soluble solvent, the tungsten compound starting material according to the present invention can be produced by sufficiently and uniformly mixing each raw material by a known means such as a ball mill.

Next, the heat treatment in the reducing gas atmosphere will be described. The starting material is preferably heat-treated at 300 ° C. or higher and 900 ° C. or lower, more preferably 500 to 800 ° C. or lower, and even more preferably 500 to 600 ° C. or lower. If the temperature is 300 ° C. or higher, the reaction for producing the composite tungsten oxide having a hexagonal structure according to the present invention proceeds, and if the temperature is 900 ° C. or lower, the composite tungsten oxide fine particles having a structure other than hexagonal or metallic tungsten is not intended. It is preferable that a side reaction product is hard to be formed.

The reducing gas at this time is not particularly limited, but H ₂ is preferable. Then, when H ₂ is used as the reducing gas, the composition of the reducing atmosphere, for example, Ar, is preferably mixed at a volume ratio of 2.0% of H ₂ in an inert gas such as N _2, more It is preferably a mixture of 0.1 to 0.8%, more preferably a mixture of 0.1 to 0.5%. When H ₂ is 0.1% to 0.8% by volume, the reduction can be efficiently promoted while controlling the reduction state under the conditions suitable for the present invention. Conditions such as the reduction temperature and reduction time, and the type and concentration of the reducing gas can be appropriately selected according to the amount of the sample.
If necessary, the reduction treatment may be carried out in a reducing gas atmosphere, and then the heat treatment may be carried out in an inert gas atmosphere. In this case, the heat treatment in the atmosphere of the inert gas is preferably performed at a temperature of 400 ° C. or higher and 1200 ° C. or lower.
As a result, a hexagonal crystal structure can be obtained. The lattice constant of the c-axis of the composite tungsten oxide fine particles is preferably 7.56 Å or more and 8.82 Å or less, and more preferably 7.56 Å or more and 7.61 Å or less. The powder color of the composite tungsten oxide fine particles ^{is 30 to 55 for L *} , -6.0 to -0.5 for a ^* , and -10 for ^{b * in the L *} a ^* b ^* color system. ~ -0.

It is preferable that the heat ray-shielding fine particles according to the present invention are surface-treated and coated with a compound containing at least one selected from Si, Ti, Zr, and Al, preferably an oxide, from the viewpoint of improving weather resistance. .. In order to carry out the surface treatment, a known surface treatment may be carried out using an organic compound containing at least one selected from Si, Ti, Zr and Al. For example, the heat ray-shielding fine particles according to the present invention and an organosilicon compound may be mixed and hydrolyzed.

[C] Heat ray-shielding fine particle dispersion liquid preferable for producing a heat ray-shielding film and heat ray-shielding glass By dispersing the heat ray-shielding fine particles according to the present invention in a liquid medium, the heat ray-shielding fine particle dispersion liquid according to the present invention can be produced. it can. The heat ray-shielding fine particle dispersion liquid is used to disperse conventional composite tungsten oxide fine particles in various fields in which other conventional materials that strongly absorb near infrared rays, for example, the composite tungsten oxide shown in Patent Document 4, have been used. It can be used in the same way as a liquid.

Hereinafter, [1] a method for producing a heat ray-shielding fine particle dispersion, which is preferable for producing a heat ray-shielding film and heat ray-shielding glass, and [2] an example of using the heat ray-shielding fine particle dispersion will be described in this order. In the present invention, the heat ray-shielding fine particle dispersion may be simply referred to as "dispersion".

[1] Method for producing heat ray-shielding fine particle dispersion liquid preferable for producing heat ray-shielding film and heat ray-shielding glass The heat ray-shielding fine particles according to the present invention and, if desired, an appropriate amount of a dispersant, a coupling agent, a surfactant, etc. By adding and performing the dispersion treatment, the heat ray-shielding fine particle dispersion liquid according to the present invention can be obtained. The medium of the heat ray-shielding fine particle dispersion liquid is required to have a function of maintaining the dispersibility of the heat ray-shielding fine particle dispersion liquid and a function of preventing coating defects from occurring when the heat ray-shielding fine particle dispersion liquid is applied. Further, if necessary, additives such as an ultraviolet absorber, an antioxidant, a light stabilizer, a tackifier, a colorant (pigment, dye, etc.), and an antistatic agent can be contained.
Hereinafter, (1) medium, (2) dispersant, coupling agent, (3) ultraviolet absorber, (4) light stabilizer, (5) antioxidant, and (6) dispersion treatment method will be described in this order. ..

(1) Medium As the medium, water, an organic solvent, an oil or fat, a liquid resin, a liquid plasticizer for plastics, or a mixture thereof can be selected to produce a heat ray-shielding dispersion. As the organic solvent satisfying the above requirements, various solvents such as alcohol-based, ketone-based, hydrocarbon-based, glycol-based, and aqueous-based solvents can be selected. Specifically, alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, butanol, pentanol, benzyl alcohol and diacetone alcohol; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone. Solvents: Ester solvents such as 3-methyl-methoxy-propionate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene Glycol derivatives such as glycol ethyl ether acetate; amides such as formamide, N-methylformamide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone; aromatic hydrocarbons such as toluene and xylene; ethylene chloride, Examples thereof include halogenated hydrocarbons such as chlorobenzene.
However, among these, organic solvents having low polarity are preferable, and in particular, isopropyl alcohol, ethanol, 1-methoxy-2-propanol, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, n-butyl acetate and the like are preferable. Is more preferable. These solvents can be used alone or in combination of two or more.

As the liquid resin, methyl methacrylate and the like are preferable. Examples of the liquid plasticizer for plastics include a plasticizer which is a compound of a monohydric alcohol and an organic acid ester, an ester-based plasticizer such as a polyhydric alcohol organic acid ester compound, and phosphorus such as an organic phosphoric acid-based plasticizer. A preferable example is an acid-based plasticizer. Of these, triethylene glycol di-2-ethylhexaonete, triethylene glycol di-2-ethylbutyrate, and tetraethylene glycol di-2-ethylhexaonate are more preferable because they have low hydrolyzability.

(2) Dispersant, coupling agent

(3) Ultraviolet Absorber By further containing the ultraviolet absorber in the heat ray-shielding fine particle dispersion according to the present invention, it is possible to further block light in the ultraviolet region, and it is possible to enhance the effect of suppressing temperature rise. .. Further, by the heat ray shielding fine particle dispersion according to the present invention contains an ultraviolet absorber, an automobile interior and buildings inside the human having a window which was affixed a heat ray shielding film produced by using the heat ray shielding fine particle dispersion It is possible to suppress the influence of ultraviolet rays on the interior and the interior, sunburn, furniture, and deterioration of the interior.

Further, the coating film containing the composite tungsten oxide particles and / or the tungsten oxide particles which are the heat ray-shielding fine particles according to the present invention may cause a light coloring phenomenon in which the transmittance is lowered by long-term exposure to strong ultraviolet rays. However, even if the heat ray-shielding fine particle dispersion liquid according to the present invention contains an ultraviolet absorber, the occurrence of the light coloring phenomenon can be suppressed.

The ultraviolet absorber is not particularly limited, and can be arbitrarily selected depending on the influence on the visible light transmittance and the like of the heat ray-shielding fine particle dispersion liquid, the ultraviolet absorption ability, the durability and the like. Examples of the ultraviolet absorber include organic ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, salicylate compounds, triazine compounds, benzotriazolyl compounds and benzoyl compounds, and inorganic ultraviolet absorbers such as zinc oxide, titanium oxide and cerium oxide. And so on. In particular, as the ultraviolet absorber, it is preferable to contain at least one selected from a benzotriazole compound and a benzophenone compound. This is because the benzotriazole compound and the benzophenone compound can make the visible light transmittance of the heat ray-shielding fine particle dispersion very high even when a concentration sufficient to absorb ultraviolet rays is added, and the long-term strong ultraviolet rays are long-term. This is because it has high durability against exposure.

Further, it is more preferable that the ultraviolet absorber contains, for example, a compound represented by the following chemical formula 1 and / or chemical formula 2.

The content of the ultraviolet absorber in the heat ray-shielding fine particle dispersion liquid according to the present invention is not particularly limited, and can be arbitrarily selected depending on the required visible light transmittance, the ultraviolet shielding ability, and the like. However, the content (content rate) of the ultraviolet absorber in the heat ray-shielding fine particle dispersion is preferably, for example, 0.02% by mass or more and 5.0% by mass or less. This is because if the content of the ultraviolet absorber is 0.02% by mass or more, the light in the ultraviolet region that cannot be completely absorbed by the composite tungsten oxide particles can be sufficiently absorbed. Further, when the content is 5.0% by mass or less, the ultraviolet absorber is more reliably prevented from precipitating in the heat ray-shielding fine particle dispersion, which greatly affects the transparency and design of the heat ray-shielding fine particle dispersion. This is because it does not give.

(4) Light Stabilizer Further, the heat ray-shielding fine particle dispersion liquid according to the present invention may further contain a hindered amine-based light stabilizer (in the present invention, it may be simply referred to as “HALS”). ..
As described above, in the heat ray shielding film or the like produced by using the heat ray shielding fine particle dispersion according to the present invention, it is possible to enhance the UV-absorbing ability by containing an ultraviolet absorber.
However environmental and that the present invention according to the heat ray shielding fine particle dispersion liquid and the heat ray shielding film or the like is practically, depending on the type of the ultraviolet absorber, an ultraviolet absorber is deteriorated with the long-term use, reduced ultraviolet absorption capacity It may end up. In contrast, when the heat ray shielding fine particle dispersion according to the present invention contains the HALS, preventing deterioration of the ultraviolet absorber, ultraviolet-absorbing capability of the heat ray shielding fine particle dispersion and heat-ray shielding film or the like according to the present invention Can contribute to the maintenance of.

As also described above, in the heat ray shielding film according to the present invention, which may cause light coloring phenomenon transmittance decreases by prolonged exposure of the strong ultraviolet radiation. Therefore, by incorporating the HALS into the heat ray shielding fine particle dispersion according to the present invention, by manufacturing a heat ray shielding film, like the case of adding metal coupling agent having an ultraviolet absorbent or an amino group, light colored The occurrence of the phenomenon can be suppressed.

Incidentally, due to containing HALS in the heat ray shielding film according to the present invention, the effect of suppressing the light colored phenomenon, the light coloring phenomenon suppressing effect due to the addition of the metal coupling agent having an amino group, specifically It is based on a different mechanism.

Therefore, the effect of suppressing the photocoloring phenomenon due to the addition of HALS and the effect of suppressing the photocoloring phenomenon due to the addition of the metal coupling agent having an amino group are not contradictory, but rather synergistic. Work for.
Further, in HALS, the compound itself may be a compound having an ability to absorb ultraviolet rays. In this case, by adding the compound, the effect of adding the above-mentioned ultraviolet absorber and the effect of adding HALS can be combined.

However, the type of HALS to be added is not limited to, but depends on the influence on the visible light transmittance of the heat ray-shielding fine particle dispersion, compatibility with an ultraviolet absorber, durability against ultraviolet rays, and the like. It can be selected arbitrarily.

Specific examples of HALS include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacade, 1- [2. -[3- (3,5-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2 , 2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3 , 8-Triazaspiro [4,5] decane-2,4-dione, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-) 4-Hydroxybenzyl) -2-n-butylmalonate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (2,2) 2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, (Mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) -1, 2,3,4-butanetetracarboxylate, Mixed {1,2,2,6,6-pentamethyl-4-piperidyl / β, β, β', β'-tetramethyl-3,9- [2,4 , 8,10-Tetraoxaspiro (5,5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, (Mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, Mixed {2,2,6,6-tetramethyl-4-piperidyl / β, β, β', β'-tetramethyl-3,9- [2 , 4,8,10-Tetraoxaspiro (5,5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidylmethacrylate, 1, , 2,2,6,6-pentamethyl-4-piperidylmethacrylate, poly [(6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl) ] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) iminol], dimethyl succinate and 4-hydroxy- Polymer of 2,2,6,6-tetramethyl-1-piperidineethanol, N, N', N'', N'''-tetrakis- (4,6-bis- (butyl- (N-methyl-) 2,2,6,6-tetramethylpiperidine-4-yl) amino) -triazine-2-yl) -4,7-diazadecan-1,10-diamine, dibutylamine-1,3,5-triazine-N , A polycondensate of N'-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethylpiperidyl) butylamine, Bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester or the like can be preferably used.

The content of HALS in the heat ray-shielding fine particle dispersion according to the present invention is not particularly limited, and can be arbitrarily selected according to the visible light transmittance, weather resistance, etc. required for the heat ray-shielding fine particle dispersion. .. The content (content rate) of HALS in the heat ray-shielding fine particle dispersion is preferably, for example, 0.05% by mass or more and 5.0% by mass or less. This is because if the content of HALS in the heat ray-shielding fine particle dispersion is 0.05% by mass or more, the effect of adding HALS can be sufficiently exerted by the heat ray-shielding fine particle dispersion. Further, when the content is 5.0% by mass or less, it is possible to more reliably prevent the precipitation of HALS in the heat ray-shielding fine particle dispersion, which has a great influence on the transparency and design of the heat ray-shielding fine particle dispersion. This is because it is not given.

(5) Antioxidant Further, the heat ray-shielding fine particle dispersion liquid according to the present invention may further contain an antioxidant (antioxidant).
When the heat ray-shielding fine particle dispersion liquid according to the present invention contains an antioxidant, other additives contained in the heat ray-shielding fine particle dispersion liquid, such as composite tungsten oxide, tungsten oxide, dispersant, coupling agent, and surfactant. Oxidative deterioration of activators, ultraviolet absorbers, HARS and the like is suppressed, and the weather resistance of the near-infrared shielding film and the like according to the present invention can be further improved.

Here, the antioxidant is not particularly limited, and can be arbitrarily selected depending on the influence on the visible light transmittance and the like of the heat ray-shielding fine particle dispersion, the desired weather resistance, and the like.
For example, a phenol-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant and the like can be preferably used.

Specific examples of antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisol, 2,6-di-t-butyl-4-ethylphenol, and stearyl-β- (3,). 5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis- (4-methyl-6-butylphenol), 2,2'-methylenebis- (4-ethyl-6-t-butylphenol) , 4,4'-butylidene-bis- (3-methyl-6-t-butylphenol), 1,1,3-tris- (2-methyl-hydroxy-5-t-butylphenyl) butane, tetrakis [methylene- 3- (3', 5'-Butyl-4-hydroxyphenyl) propionate] methane, 1,3,3-tris- (2-methyl-4-hydroxy-5-t-butylphenol) butane, 1,3,5 -Methyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, and bis (3,3'-t-butylphenol) butyric acid glycol ester, isooctyl-3 − (3,5-di-t-butyl-4-hydroxyphenyl) propionate and the like can be preferably used.

The content of the antioxidant in the heat ray-shielding fine particle dispersion is not particularly limited, and can be arbitrarily selected depending on the visible light transmittance, weather resistance, etc. required for the heat ray-shielding fine particle dispersion. However, the content (content rate) of the antioxidant in the heat ray-shielding fine particle dispersion is preferably, for example, 0.05% by mass or more and 5.0% by mass or less. This is because if the content of the antioxidant is 0.05% by mass or more, the effect of adding the antioxidant can be sufficiently exerted in the heat ray-shielding fine particle dispersion. Further, when the content is 5.0% by mass or less, it is possible to more reliably prevent the antioxidant from precipitating in the heat ray-shielding fine particle dispersion, which greatly improves the transparency and design of the heat ray-shielding fine particle dispersion. This is because it does not affect it.

(6) Dispersion Treatment Method The method for dispersing the heat ray-shielding fine particle dispersion liquid according to the present invention can be arbitrarily selected from known methods as long as the heat ray-shielding fine particles are uniformly dispersed in the liquid medium. Methods such as a ball mill, a sand mill, and ultrasonic dispersion can be used.
In order to obtain a uniform heat ray-shielding fine particle dispersion, various additives and dispersants may be added or the pH may be adjusted.

The content of the heat ray-shielding fine particles in the above-mentioned heat ray-shielding fine particle dispersion is preferably 0.01% by mass to 50% by mass. If it is 0.01% by mass or more, it can be suitably used for manufacturing a coating film or a plastic molded body described later, and if it is 50% by mass or less, industrial production is easy. More preferably, it is 1% by mass or more and 35% by mass or less.

The heat ray-shielding fine particle dispersion liquid according to the present invention in which such heat ray-shielding fine particles are dispersed in a liquid medium is placed in an appropriate transparent container, and the light transmittance is measured as a function of wavelength using a spectrophotometer. be able to. The heat ray-shielding fine particle dispersion liquid according to the present invention has a visible light transmittance of 85% when only the light absorption by the heat ray-shielding fine particles is calculated (in the embodiment according to the present invention, the visible light transmittance is simply "85%". In the case of), the transmittance of near-infrared light at a wavelength of 800 to 900 nm is 30% or more and 60% or less, and the average value of the transmittance in the wavelength range of 1200 to 1500 nm is 20%. And the transmittance at a wavelength of 2100 nm is 22% or less.
In the measurement, adjusting the visible light transmittance to 85% when only the light absorption by the heat ray-shielding fine particles contained in the heat ray-shielding fine particle dispersion is calculated has compatibility with the dispersion solvent or the dispersion solvent. This is facilitated by diluting with an appropriate solvent.

The light transmittance profile of the heat ray-shielding fine particle dispersion liquid according to the present invention described above has a wavelength of 1200 as compared with the light transmittance profile when the composite tungsten oxide fine particles shown in Patent Documents 4 and 5 are used. It has a transmittance of near-infrared light in the wavelength range of 800 to 900 nm without significantly increasing the transmittance in the range of ~ 1500 nm, and has an improved heat ray absorbing ability in the wavelength range of 2100 nm.

[2] Example of use of heat ray-shielding fine particle dispersion liquid By dispersing the heat ray-shielding fine particle dispersion liquid or the heat ray-shielding fine particle dispersion liquid according to the present invention in a solid medium, dispersion powder, masterbatch, heat ray-shielding film, heat ray-shielding plastic molding The body etc. can be manufactured.

As an example of a general usage method, a method for producing a heat ray shielding film using the heat ray shielding fine particle dispersion liquid according to the present invention will be described. A heat ray-shielding film can be produced by mixing the above-mentioned heat ray-shielding fine particle dispersion with a plastic or a monomer to prepare a coating liquid and forming a coating film on a substrate by a known method.

As the medium of the coating film, for example, UV curable resin, thermosetting resin, electron beam curable resin, room temperature curable resin, thermoplastic resin and the like can be selected according to the purpose. Specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate resin, fluorine resin, polycarbonate resin, acrylic resin. , Polyvinyl butyral resin can be mentioned. These resins may be used alone or in combination. It is also possible to use a binder using a metal alkoxide. Typical examples of the metal alkoxide are alkoxides such as Si, Ti, Al, and Zr. Binders using these metal alkoxides can form an oxide film by hydrolyzing and polycondensing by heating or the like.

The base material may be a film as described above, but may be a board if desired, and the shape is not limited. As the transparent base material, PET, acrylic, urethane, polycarbonate, polyethylene, ethylene-vinyl acetate copolymer, vinyl chloride, fluororesin and the like can be used according to various purposes. In addition to resin, glass can be used.

[D] Method for manufacturing heat ray-shielding film and heat ray-shielding glass Using the above-mentioned heat ray-shielding fine particle dispersion, a coating layer containing heat ray-shielding fine particles is formed on a substrate film or a transparent substrate selected from the substrate glass. This makes it possible to manufacture a heat ray shielding film or a heat ray shielding glass.

A heat ray shielding film or a heat ray shielding glass is produced by mixing the above-mentioned heat ray shielding fine particle dispersion liquid with a plastic or a monomer to prepare a coating liquid and forming a coating film on a transparent substrate by a known method. Can be done.
For example, the heat ray shielding film can be produced as follows.
A medium resin is added to the above-mentioned heat ray-shielding fine particle dispersion liquid to obtain a coating liquid. After coating the surface of the film substrate with this coating liquid, the solvent is evaporated and the resin is cured by a predetermined method, so that a coating film in which the heat ray-shielding fine particles are dispersed in the medium can be formed.

As the medium resin of the coating film, for example, UV curable resin, thermosetting resin, electron beam curable resin, room temperature curable resin, thermoplastic resin and the like can be selected according to the purpose. Specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate resin, fluorine resin, polycarbonate resin, acrylic resin. , Polyvinyl butyral resin can be mentioned.
These resins may be used alone or in combination. However, among the media for the coating layer, it is particularly preferable to use a UV curable resin binder from the viewpoint of productivity and equipment cost.

It is also possible to use a binder using a metal alkoxide. Typical examples of the metal alkoxide are alkoxides such as Si, Ti, Al, and Zr. Binders using these metal alkoxides can form a coating layer made of an oxide film by hydrolyzing and polycondensing by heating or the like.

The film base material described above is not limited to the film shape, and may be, for example, a board shape or a sheet shape. As the film base material, PET, acrylic, urethane, polycarbonate, polyethylene, ethylene vinyl acetate copolymer, vinyl chloride, fluororesin and the like can be used according to various purposes. However, as the heat ray shielding film, a polyester film is preferable, and a PET film is more preferable.
Further, the surface of the film substrate is preferably surface-treated in order to realize easy adhesion of the coating layer. Further, in order to improve the adhesiveness between the glass substrate or the film substrate and the coating layer, it is also preferable to form an intermediate layer on the glass substrate or the film substrate and form the coating layer on the intermediate layer. The composition of the intermediate layer is not particularly limited, and may be composed of, for example, a polymer film, a metal layer, an inorganic layer (for example, an inorganic oxide layer such as silica, titania, or zirconia), an organic / inorganic composite layer, or the like. ..

The method of providing the coating layer on the substrate film or the substrate glass is not particularly limited as long as it can uniformly apply the heat ray-shielding fine particle-containing dispersion liquid to the surface of the substrate. For example, a bar coat method, a gravure coat method, a spray coat method, a dip coat method and the like can be mentioned.
For example, according to the bar coating method using a UV curable resin, a coating liquid in which the liquid concentration and additives are appropriately adjusted so as to have appropriate leveling property is used for the purpose of adjusting the thickness of the coating film and the content of the heat ray-shielding fine particles. A coating film can be formed on a substrate film or a substrate glass by using a wire bar having a bar number capable of satisfying. Then, the organic solvent contained in the coating liquid is removed by drying, and then the coating layer is formed on the substrate film or the substrate glass by irradiating with ultraviolet rays and curing. At this time, the drying conditions of the coating film vary depending on each component, the type of solvent, and the ratio of use, but are usually about 20 seconds to 10 minutes at a temperature of 60 ° C. to 140 ° C. The irradiation of ultraviolet rays is not particularly limited, and a UV exposure machine such as an ultra-high pressure mercury lamp can be preferably used.
In addition, the adhesion between the substrate and the coating layer, the smoothness of the coating film at the time of coating, the drying property of the organic solvent, and the like can be controlled by the steps before and after the formation of the coating layer. Examples of the pre- and post-processes include a substrate surface treatment step, a pre-baking (pre-heating of the substrate) step, and a post-baking (post-heating of the substrate) step, which can be appropriately selected. The heating temperature in the pre-baking step and / or the post-baking step is preferably 80 ° C. to 200 ° C., and the heating time is preferably 30 seconds to 240 seconds.

The thickness of the coating layer on the substrate film or the substrate glass is not particularly limited, but is preferably 10 μm or less, and more preferably 6 μm or less in practical use. This is because when the thickness of the coating layer is 10 μm or less, in addition to exhibiting sufficient pencil hardness and having scratch resistance, warpage of the substrate film occurs during volatilization of the solvent in the coating layer and curing of the binder. This is because it is possible to avoid the occurrence of process abnormalities such as.

The content of the heat ray-shielding fine particles contained in the coating layer is not particularly limited, but the content per projected area of the film / glass / coating layer is 0.1 g / m ² or more and 5.0 g / m ² or less. Is preferable. If the content is 0.1 g / m ² or more, the heat ray shielding property can be significantly exhibited as compared with the case where the heat ray shielding fine particles are not contained, and if the content is 5.0 g / m ² or less, the heat ray shielding property can be exhibited significantly. This is because the shielding film / glass / coating layer maintains sufficient visible light transmission.

The optical characteristics of the manufactured heat ray shielding film and heat ray shielding glass are such that when the visible light transmittance is 70%, the transmittance at a wavelength of 850 nm is 23% or more and 45% or less, and the wavelength is in the range of 1200 to 1500 nm. The average value of the transmittance is 20% or less. The visible light transmittance can be easily adjusted to 70% by adjusting the concentration of heat ray-shielding fine particles in the coating liquid or adjusting the film thickness of the coating layer.

The above-mentioned limiting value of the transmittance profile generally exists in the range of 1200 to 1500 nm as compared with the transmittance profile when the composite tungsten oxide fine particles according to the conventional technique having a composition equivalent to this except for the element M are used. The width of the visible light transmitting band is widened to the long wavelength side without significantly increasing the average value of the transmittance to be applied, and the transmittance is higher in the range of 800 to 900 nm. The above-mentioned limiting values of the transmittance profile have a certain width even when composite tungsten oxide fine particles having the same composition and concentration are used, and it determines the size and shape of the fine particles, the state of aggregation, and the dispersant. It should be noted that it can be changed depending on the refractive index of the dispersion solvent contained therein.

Further, in order to further impart an ultraviolet shielding function to the heat ray shielding film and the heat ray shielding glass according to the present invention, at least one kind of inorganic particles such as titanium oxide, zinc oxide and cerium oxide, and organic benzophenone and benzotriazole. The above may be added.

Further, in order to improve the visible light transmittance of the heat ray shielding film and the heat ray shielding glass according to the present invention, particles such as ATO, ITO, aluminum-added zinc oxide, and indium tin composite oxide are further mixed in the coating layer. May be good. By adding these transparent particles to the coating layer, the transmittance near the wavelength of 750 nm increases, while the transmittance of near-infrared light is high and the heat ray is high because infrared light having a wavelength longer than 1200 nm is blocked. A heat ray shield having high shielding characteristics can be obtained.

The optical characteristics of the heat ray-shielding film or heat ray-shielding glass according to the present invention are such that when the visible light transmittance is 70%, the average value of the transmittance at a wavelength of 800 to 900 nm is 13% or more and 40% or less, and the wavelength is The average value of the transmittance existing in the range of 1200 to 1500 nm is 8% or less, and the transmittance at the wavelength of 2100 nm is 5% or less.

Here, adjusting the visible light transmittance to 70% means that the concentration of the heat ray-shielding fine particles contained in the above-mentioned organic solvent dispersion liquid, dispersion powder, plasticizer dispersion liquid or masterbatch, and the resin composition are prepared. It is easy by adjusting the amount of heat ray-shielding fine particles, dispersion powder, plasticizer dispersion liquid or masterbatch added, and the film thickness of the film.

It has been found that the shape of the transmittance profile of the heat ray-shielding fine particles according to the present invention described above has the following features as compared with the transmittance profile when the composite tungsten oxide fine particles according to the conventional technique are used. ..
1. 1. The heat ray-shielding fine particles according to the present invention have a visible light transmitting band region extending to a region of near infrared light having a wavelength of 800 to 900 nm, and have a high transmittance in the region.
2. The heat ray-shielding fine particles according to the present invention hardly change the value of the average value of the transmittance existing in the wavelength region of 1200 to 1500 nm.
3. 3. The heat ray-shielding fine particles according to the present invention have a heat ray-shielding performance having a wavelength of 2100 nm.

Hereinafter, the present invention will be described in more detail with reference to Examples.
However, the present invention is not limited to the following examples.

In Examples 1 to 3 and Comparative Example 1, the powder color of the heat ray-shielding fine particles was measured using a spectrophotometer U-4100 manufactured by Hitachi, Ltd., and evaluated by the ^{L *} a ^* b ^{* color system.} ..
Further, in Examples 1 to 3 and Comparative Example 1, the transmittance of the heat ray-shielding fine particle dispersion liquid with respect to light having a wavelength of 300 to 2100 nm is determined by a cell for a spectrophotometer (manufactured by GL Science Co., Ltd., model number: S10-SQ-1, The dispersion was held in a material: synthetic quartz, optical path length: 1 mm), and the measurement was performed using a spectrophotometer U-4100 manufactured by Hitachi, Ltd.
At the time of the measurement, the transmittance was measured with the solvent of the dispersion liquid (methyl isobutyl ketone) filled in the above-mentioned cell, and the baseline of the transmittance measurement was determined. As a result, the spectral transmittance and the visible light transmittance described below exclude the contribution of the light reflection of the cell surface for the spectrophotometer and the light absorption of the solvent, and only the light absorption by the heat ray shielding fine particles is calculated. It will be.

Specifically, the transmittance when the visible light transmittance is 85% can be obtained by the following procedure.
First, the transmittance T1 (λ) of the spectrophotometer cell filled with methyl isobutyl ketone is measured. Next, the transmittance T2 (λ) of the spectrophotometer cell filled with the dispersion liquid containing the heat ray absorbing fine particles is measured. Then, as shown in Equation 2, T2 (λ) is divided by T1 (λ).
T3 (λ) = 100 × T2 (λ) / T1 (λ) ・ ・ ・ ・ ・ ・ ・ ・ Equation 2
Here, T3 (λ) is a transmittance curve as heat ray absorbing fine particles excluding the influence of absorption and reflection of the base material. In addition, λ means a wavelength.

Therefore, the transmittance curve T4 (λ) when the visible light transmittance is 85% can be calculated by the equation of Lambert-Beer.
T4 (λ) = 100 × (T3 (λ) / 100) ^ a ... Equation 3
In addition, "^" is a mathematical symbol meaning a power, and A ^ B means "A to the B power". Further, "a" is a variable that takes a real value. The specific value of a is determined so that the visible light transmittance calculated by JIS R 3106 based on T4 (λ) is 85%.

The average dispersed particle size of the heat ray-shielding fine particles was measured using a Microtrack particle size distribution meter manufactured by Nikkiso Co., Ltd.
The average particle size of the heat ray-shielding fine particles was measured using a Microtrack particle size distribution meter manufactured by Nikkiso Co., Ltd.

In Examples 4 to 16 and Comparative Examples 4 to 6, the transmittances of the heat ray shielding film, the heat ray shielding glass, the heat ray shielding sheet, and the combined transparent base material in each example are the spectral luminosity manufactured by Hitachi, Ltd. described above. Measured with a meter U-4100, the visible light transmittance was calculated based on JIS R 3106: 1998 based on the measured light transmittance in the wavelength region of 300 to 2100 nm.

[Example 1] (heat ray shielding film using _{Cs 0.30} WO ₃₎
Each powder of tungstic acid (H ₂ WO ₄ ) and cesium hydroxide (CsOH) is weighed at a ratio equivalent to Cs / W (molar ratio) = 0.30 / 1.00, and then sufficiently mixed in an agate mortar. It was made into a mixed powder. The mixed powder is _{heated under a 0.3% H 2 gas supply using N 2} gas as a carrier and subjected to a reduction treatment at a temperature of 500 ° C. for 4 hours, and then at 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} calcined to have a hexagonal, 7.4131Å lattice constant of a-axis, a lattice constant of c-axis 7.5885Å, powder ^color, the L ^* a * ^{b *} color system, ^{L *} is A cesium tungsten bronze powder (hereinafter, abbreviated as “powder A”) having 41.86, a ^* of -2.90, and b ^{* of −6.76 was obtained.} The measurement results are shown in Table 1.
Acrylic polymer dispersant having 20% by mass of powder A and a group containing an amine as a functional group (amine value 48 mgKOH / g, acrylic dispersant having a decomposition temperature of 250 ° C.) (hereinafter, abbreviated as "dispersant a". ) 10% by mass and 70% by mass of methyl isobutyl ketone were weighed. These were _{loaded into a paint shaker containing 0.3 mmφZrO 2} beads, and pulverized and dispersed for 10 hours to obtain a heat ray-shielding fine particle dispersion (hereinafter, abbreviated as “dispersion A”). Here, the average dispersed particle size of the heat ray-shielding fine particles in the dispersion liquid A was measured and found to be 25 nm.

The dispersion liquid A was appropriately diluted with MIBK and placed in a rectangular container having a thickness of 10 mm, and the spectral transmittance was measured. From the transmittance profile when the transmittance was adjusted so that the visible light transmittance was 85%, the average value of the transmittance at a wavelength of 800 to 900 nm was 45.5%, and the transmittance at a wavelength of 1200 to 1500 nm. The average value was 12.8%, and the transmittance at a wavelength of 2100 nm was 15.5%. It was confirmed that the visible light transmission band was clearly wider and the heat ray shielding performance at a wavelength of 2100 nm was improved as compared with the cesium tungsten bronze produced by the conventional method shown in Comparative Example 1 below. The measurement results of the powder color of the powder A are shown in Table 1, and the measurement results of the transmittance are shown in Table 2.

50 parts by weight of Toagosei's Aronix UV-3701 (hereinafter referred to as UV-3701), which is an ultraviolet curable resin for hard coating, is mixed with 100 parts by weight of the dispersion liquid A to form a heat ray shielding fine particle coating liquid (hereinafter referred to as coating). Liquid A) was prepared, and this coating liquid was applied onto a PET film (HPE-50 manufactured by Teijin) using a bar coater to form a coating film. The same PET film was used in other Examples and Comparative Examples.
A PET film provided with a coating film was dried at 80 ° C. for 60 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to prepare a heat ray-shielding film provided with a coating film containing heat ray-shielding fine particles. ..

In the above-mentioned preparation of the heat ray-shielding film, the concentration of the heat ray-shielding fine particles in the coating liquid and the film thickness of the coating film were adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray shielding film were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 27.9%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 4.2%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 5.4%, and the haze was measured to be 0.9%. The results are shown in Table 3, and the transmittance profile for each wavelength is shown in FIG.

[Example 2] (heat ray shielding film using _{Cs 0.20} WO ₃₎
Each powder of tungstic acid (H ₂ WO ₄ ) and cesium hydroxide (CsOH) is weighed at a ratio equivalent to Cs / W (molar ratio) = 0.20 / 1.00, and then sufficiently mixed in an agate mortar. It was made into a mixed powder. The mixed powder is _{heated under a 0.8% H 2 gas supply using N 2} gas as a carrier and subjected to a reduction treatment at a temperature of 550 ° C. for 20 minutes, and then at 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} calcined to have a hexagonal, 7.4143Å lattice constant of a-axis, a lattice constant of c-axis 7.5766Å, powder ^color, the L ^* a * ^{b *} color system, ^{L *} is A cesium tungsten bronze powder (hereinafter, abbreviated as “powder B”) having 47.55, a ^* of −5.16, and b ^{* of −6.07 was obtained.} The measurement results are shown in Table 1.
Acrylic polymer dispersant having 20% by mass of powder B and a group containing an amine as a functional group (amine value 48 mgKOH / g, acrylic dispersant having a decomposition temperature of 250 ° C.) (hereinafter, referred to as dispersant b) 10 Weighed% by mass and 70% by mass of methyl isobutyl ketone. These were _{loaded into a paint shaker containing 0.3 mmφZrO 2} beads, and pulverized and dispersed for 10 hours to obtain a heat ray-shielding fine particle dispersion (hereinafter, abbreviated as “dispersion B”). Here, the average dispersed particle size of the heat ray-shielding fine particles in the dispersion liquid B was measured and found to be 23 nm.

The spectral transmittance was measured in the same manner as in Example 1 except that the dispersion liquid B was used. From the transmittance profile when the transmittance was adjusted so that the visible light transmittance was 85%, the average value of the transmittance at a wavelength of 800 to 900 nm was 55.7%, and the transmittance at a wavelength of 1200 to 1500 nm. The average value was 18.3%, and the transmittance at a wavelength of 2100 nm was 18.5%. It was confirmed that the visible light transmission band was clearly wider and the heat ray shielding performance at a wavelength of 2100 nm was improved as compared with the cesium tungsten bronze produced by the conventional method shown in Comparative Example 1 below. The measurement results of the powder color of the powder B are shown in Table 1, and the measurement results of the transmittance are shown in Table 2.

A heat ray-shielding film provided with a coating film containing heat ray-shielding fine particles was produced in the same manner as in Example 1 except that the dispersion liquid B was used as a heat ray-shielding coating liquid (hereinafter referred to as coating liquid B).

In the above-mentioned preparation of the heat ray-shielding film, the concentration of the heat ray-shielding fine particles in the coating liquid and the film thickness of the coating film were adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray shielding film were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 37.7%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 7.2%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 7.0%, and the haze was measured to be 1.0%. The results are shown in Table 3, and the transmittance profile for each wavelength is shown in FIG.

[Example 3] (heat ray shielding film using _{Cs 0.33} WO ₃₎
Each powder of tungstic acid (H ₂ WO ₄ ) and cesium hydroxide (CsOH) is weighed at a ratio equivalent to Cs / W (molar ratio) = 0.33 / 1.00, and then sufficiently mixed in an agate mortar. It was made into a mixed powder. The mixed powder is _{heated under a 0.3% H 2 gas supply using N 2} gas as a carrier and subjected to a reduction treatment at a temperature of 500 ° C. for 6 hours, and then at 800 ° C. for 1 hour in _{an N 2 gas atmosphere.} calcined to have a hexagonal, 7.4097Å lattice constant of a-axis, a lattice constant of c-axis 7.6033Å, powder ^color, the L ^* a * ^{b *} color system, ^{L *} is A cesium tungsten bronze powder (hereinafter, abbreviated as “powder C”) having 39.58, a ^* of −1.63, and b ^{* of −7.33 was obtained.} The measurement results are shown in Table 1.
Acrylic polymer dispersant having 20% by mass of powder C and a group containing an amine as a functional group (amine value 48 mgKOH / g, acrylic dispersant having a decomposition temperature of 250 ° C.) (hereinafter, referred to as dispersant c) 10 Weighed% by mass and 70% by mass of methyl isobutyl ketone. These were _{loaded into a paint shaker containing 0.3 mmφZrO 2} beads, and pulverized and dispersed for 10 hours to obtain a heat ray-shielding fine particle dispersion (hereinafter, abbreviated as “dispersion C”). Here, the average dispersed particle size of the heat ray-shielding fine particles in the dispersion liquid B was measured and found to be 25 nm.

The spectral transmittance was measured in the same manner as in Example 1 except that the dispersion liquid C was used. From the transmittance profile when the transmittance was adjusted so that the visible light transmittance was 85%, the average value of the transmittance at a wavelength of 800 to 900 nm was 33.4%, and the transmittance at a wavelength of 1200 to 1500 nm. The average value was 11.6%, and the transmittance at a wavelength of 2100 nm was 21.4%. It was confirmed that the visible light transmission band was clearly wider and the heat ray shielding performance at a wavelength of 2100 nm was improved as compared with the cesium tungsten bronze produced by the conventional method shown in Comparative Example 1 below. The measurement results of the powder color of the powder C are shown in Table 1, and the measurement results of the transmittance are shown in Table 2.

A heat ray-shielding film provided with a coating film containing heat ray-shielding fine particles was produced in the same manner as in Example 1 except that the dispersion liquid C was used as a heat ray-shielding coating liquid (hereinafter referred to as coating liquid C).

In the above-mentioned preparation of the heat ray-shielding film, the concentration of the heat ray-shielding fine particles in the coating liquid and the film thickness of the coating film were adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray shielding film were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 17.6%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 3.6%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 8.7%, and the haze was measured to be 1.0%. The results are shown in Table 3, and the transmittance profile for each wavelength is shown in FIG.

[Example 4] (heat ray shielding film using _{Cs 0.33} WO ₃₎
1 part by mass of a benzotriazole-based ultraviolet absorber (manufactured by BASF, TINUVIN384-2) containing a benzotriazole compound in 100 parts by mass of powder C, and bis decanoate (2,2,6,6-tetramethyl-1- (octyl)). 1 part by mass of aminoether-based HALS (manufactured by BASF, TINUVIN123) containing a reaction product of oxy) -4-piperidinyl ester, 1,1-dimethylethylhydroperoxide and octane, as an antioxidant, isooctyl-3- ( A hindered phenolic antioxidant (manufactured by BASF, trade name IRGANOX1135) containing 3,5-di-t-butyl-4-hydroxyphenyl) propionate was weighed to 1 part by mass. These were _{loaded into a paint shaker containing 0.3 mmφZrO 2} beads, and pulverized and dispersed for 10 hours to obtain a heat ray-shielding fine particle dispersion (hereinafter, abbreviated as “dispersion D”). Here, the average dispersed particle size of the heat ray-shielding fine particles in the dispersion liquid D was measured and found to be 25 nm.

The spectral transmittance was measured in the same manner as in Example 1 except that the dispersion liquid D was used. From the transmittance profile when the transmittance was adjusted so that the visible light transmittance was 85%, the average value of the transmittance at a wavelength of 800 to 900 nm was 34.2%, and the transmittance at a wavelength of 1200 to 1500 nm. The average value was 10.4%, and the transmittance at a wavelength of 2100 nm was 21.2%. It was confirmed that the visible light transmission band was clearly wider and the heat ray shielding performance at a wavelength of 2100 nm was improved as compared with the cesium tungsten bronze produced by the conventional method shown in Comparative Example 1 below. The measurement results of the transmittance are shown in Table 2.

A heat ray-shielding film provided with a coating film containing heat ray-shielding fine particles was produced in the same manner as in Example 1 except that the dispersion liquid D was used as a heat ray-shielding coating liquid (hereinafter referred to as coating liquid D).

In the above-mentioned preparation of the heat ray-shielding film, the concentration of the heat ray-shielding fine particles in the coating liquid and the film thickness of the coating film were adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray shielding film were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 17.6%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 3.6%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 8.7%, and the haze was measured to be 1.0%. The results are shown in Table 3, and the transmittance profile for each wavelength is shown in FIG.

[Comparative Example 1] (Heat ray shielding film using _{Cs 0.33} WO _{3)
Example 3 except that the mixture was heated under a 5% H 2} gas supply using N ₂ gas as a carrier, subjected to a reduction treatment at a temperature of 550 ° C. for 1 hour, and then calcined at 800 ° C. for 1 hour in an _{N 2 gas atmosphere.} In the same manner as above, it has hexagonal crystals, the a-axis lattice constant is 7.4080 Å, the c-axis lattice constant is 7.6111 Å, and the powder color is L ^* a ^* b ^{* in the} L * a * b * color system ^. The cesium tungsten bronze powder according to Comparative Example 1 (hereinafter, abbreviated as “powder E”) was obtained, in which 36.11, a ^* was 0.52, and b ^{* was −5.54.} The measurement results are shown in Table 1.
When a dispersion of this powder was prepared using a paint shaker together with a dispersant and a solvent, the average dispersed particle size was 23 nm.
Then, when the spectral transmittance was measured by adjusting the dilution rate so that the visible light transmittance was 85%, the average value of the transmittance at a wavelength of 800 to 900 nm was 26.0 from the transmittance profile. The average value of the transmittance at a wavelength of 1200 to 1500 nm was 13.3%, and the transmittance at a wavelength of 2100 nm was 24.4%.
From the above, it was confirmed that the average value of the transmittance at a wavelength of 800 to 900 nm was lower and the transmittance of the transmittance at a wavelength of 2100 nm was higher than in Examples 1 to 3. The measurement results of the powder color of the powder E are shown in Table 1, and the measurement results of the transmittance are shown in Table 2.

A heat ray-shielding film provided with a coating film containing heat ray-shielding fine particles was produced in the same manner as in Example 1 except that the dispersion liquid E was used as a heat ray-shielding coating liquid (hereinafter referred to as coating liquid E).

In the above-mentioned preparation of the heat ray-shielding film, the concentration of the heat ray-shielding fine particles in the coating liquid and the film thickness of the coating film were adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray shielding film were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 12.1%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 4.5%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 10.6%, and the haze was measured to be 0.9%. The results are shown in Table 3, and the transmittance profile for each wavelength is shown in FIG.

[Example 5] (heat ray shielding glass using _{Cs 0.30} WO ₃₎
The coating liquid A was applied on an inorganic clear glass of 10 cm × 10 cm × 2 mm with a bar coater to form a coating film. The coating film was dried at 80 ° C. for 60 seconds to evaporate the solvent, and then cured with a high-pressure mercury lamp to prepare a heat ray-shielding glass having a coating film containing heat ray-shielding fine particles.

In the above-mentioned production of the heat ray-shielding glass, the concentration of the heat ray-shielding fine particles in the coating liquid or the film thickness of the coating film was adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray-shielding glass were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 24.3%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 3.2%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 4.5%, and the haze was measured to be 0.5%. The results are shown in Table 4.

[Example 6] (heat ray shielding glass using _{Cs 0.20} WO ₃₎
A heat ray-shielding glass was produced in the same manner as in Example 5 except that the coating liquid B was used.

In the above-mentioned production of the heat ray-shielding glass, the concentration of the heat ray-shielding fine particles in the coating liquid or the film thickness of the coating film was adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray-shielding glass were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 33.4%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 5.7%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 6.0%, and the haze was measured to be 0.4%. The results are shown in Table 4.

[Example 7] (heat ray shielding glass using _{Cs 0.33} WO ₃₎
A heat ray-shielding glass was produced in the same manner as in Example 5 except that the coating liquid C was used.

In the above-mentioned production of the heat ray-shielding glass, the concentration of the heat ray-shielding fine particles in the coating liquid or the film thickness of the coating film was adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray-shielding glass were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 14.9%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 2.7%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 7.5%, and the haze was measured to be 0.5%. The results are shown in Table 4.

[Example 8] (heat ray shielding glass using _{Cs 0.33} WO ₃₎
A heat ray-shielding glass was produced in the same manner as in Example 5 except that the coating liquid D was used.

In the above-mentioned production of the heat ray-shielding glass, the concentration of the heat ray-shielding fine particles in the coating liquid or the film thickness of the coating film was adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray-shielding glass were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 14.9%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 2.7%, and the wavelength was measured. The transmittance at 2100 nm was measured to be 7.5%, and the haze was measured to be 0.5%. The results are shown in Table 4.

[Comparative Example 2] (heat ray shielding glass using _{Cs 0.33} WO ₃₎
A heat ray-shielding glass was produced in the same manner as in Example 5 except that the coating liquid E was used.

In the above-mentioned production of the heat ray-shielding glass, the concentration of the heat ray-shielding fine particles in the coating liquid or the film thickness of the coating film was adjusted to set the visible light transmittance to 70%.
When the optical characteristics of this heat ray-shielding glass were measured, the average value of the transmittance at a wavelength of 800 to 900 nm was 10.0%, the average value of the transmittance at a wavelength of 1200 to 1500 nm was 3.4%, and the wavelength was measured from the transmittance profile. The transmittance at 2100 nm was measured to be 9.2%, and the haze was measured to be 0.5%. The results are shown in Table 4.

[Evaluation of Examples 1 to 8 and Comparative Examples 1 and 2]
The heat ray-shielding fine particles according to Examples 1 to 8 have a near-red wavelength of 800 to 900 nm when the visible light transmittance is 85% as compared with Comparative Examples 1 and 2 which are conventional composite tungsten oxide fine particles. The average value of the transmittance of external light is high, and the transmittance at wavelengths of 1200 to 1800 nm and wavelength of 2100 nm is low. From this result, it was found that while ensuring the high heat-shielding characteristics exhibited by the composite tungsten oxide fine particles, high transmittance can be obtained with near-infrared light having a wavelength of 800 to 900 nm, and the tingling sensation on the skin is reduced. ..

The heat ray-shielding film according to Examples 1 to 4 and the heat ray-shielding glass according to Examples 5 to 8 are a heat ray-shielding film using the conventional composite tungsten oxide fine particles according to Comparative Example 1 and the conventional composite according to Comparative Example 2. When the visible light transmittance is 85%, the average value of the transmittance of near-infrared light having a wavelength of 800 to 900 nm is higher than that of the heat ray-shielding glass using tungsten oxide fine particles, and the wavelength is 1200 to 1800 nm and the wavelength is 2100 nm. Transmittance is low. From this result, it was found that while ensuring the high heat-shielding characteristics exhibited by the composite tungsten oxide fine particles, high transmittance can be obtained with near-infrared light having a wavelength of 800 to 900 nm, and the tingling sensation on the skin is reduced. ..

Claims (10)

It is a composite tungsten oxide fine particle having a heat ray shielding function, and when the visible light transmittance when only the light absorption by the composite tungsten oxide fine particle is calculated is 85%, the transmittance in the wavelength range of 800 to 900 nm. The average value of is 30% or more and 60% or less, the average value of the transmittance in the wavelength range of 1200 to 1500 nm is 10.4% or more and 20% or less, and the transmittance of the wavelength of 2100 nm is 15.5. A heat ray-shielding film or heat ray-shielding glass comprising % or more and 22% or less of heat ray-shielding fine particles. The heat ray shielding film or heat ray shielding film according to claim 1, wherein the composite tungsten oxide fine particles have a hexagonal crystal structure and the lattice constant of the c-axis is 7.56 Å or more and 8.82 Å or less. Glass. A claim characterized in that a coating layer is provided on at least one surface of a transparent base material selected from a transparent film base material or a transparent glass base material, and the coating layer is a binder resin layer containing the heat ray-shielding fine particles. Item 2. The heat ray-shielding film or heat ray-shielding glass according to Item 1. The heat ray shielding film or heat ray shielding glass according to claim 3, wherein the binder resin is a UV curable resin binder. The heat ray shielding film or heat ray shielding glass according to claim 3 or 4, wherein the thickness of the coating layer is 10 μm or less. The heat ray shielding film according to any one of claims 3 to 5, wherein the transparent film base material is a polyester film. The heat ray-shielding film according to any one of claims 3 to 6, wherein the content of the heat ray-shielding fine particles contained in the coating layer per unit projected area is 0.1 g / m ² or more and 5.0 g / m ^{2 or less.} Or heat ray shielding glass. It is a heat ray shielding film, and when the visible light transmittance is 70%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 13% or more and 40% or less, and the transmittance is in the wavelength range of 1200 to 1500 nm. Whether the average value of the rate is 3.6% or more and 8% or less and the transmittance at a wavelength of 2100 nm is 5.4% or more and 9% or less.
Alternatively, in the case of heat ray shielding glass, when the visible light transmittance is 70%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 13% or more and 40% or less, and the wavelength is in the range of 1200 to 1500 nm. According to any one of claims 1 to 7, wherein the average value of the transmittance in the above is 2.7% or more and 8% or less, and the transmittance at a wavelength of 2100 nm is 4.5% or more and 9% or less. The heat ray shielding film or heat ray shielding glass described. A mixing step of mixing tungstic acid and a hydroxide powder of one or more elements selected from Cs, Rb, K, Tl, and Ba at a predetermined ratio to obtain a mixed powder.
The mixed powder, the inert gas performs a reduction treatment by heating under H ₂ gas supply from 0.1 to 0.5% of the carrier, one selected Cs, Rb, K, Tl, Ba, A firing process for obtaining a composite tungsten oxide powder containing the above elements,
A step of uniformly mixing the composite tungsten oxide powder into a transparent resin to obtain a heat ray-shielding fine particle dispersion, and
A method for producing a heat ray-shielding film or heat ray-shielding glass, which comprises a step of coating the heat ray-shielding fine particle dispersion on a transparent film base material or a transparent glass base material.
However, the composite tungsten oxide powder has a hexagonal crystal structure, the lattice constant of the c-axis is 7.56 Å or more and 8.82 Å or less, and the powder color is L ^* a ^* b ^* color. In the system, it contains composite tungsten oxide fine particles in which ^{L *} is 30 to 55, a ^* is −6.0 to −0.5, and b ^{* is −10 to −0.}
When the visible light transmittance when only the light absorption by the composite tungsten oxide fine particles is calculated is 85%, the average value of the transmittance in the wavelength range of 800 to 900 nm is 30% or more and 60% or less, and The average value of the transmittance in the wavelength range of 1200 to 1500 nm is 10.4% or more and 20% or less, and the transmittance at the wavelength of 2100 nm is 15.5% or more and 22% or less. The heat ray shielding glass or heat ray shielding film according to any one of claims 1 to 8, further comprising one or more selected from an ultraviolet absorber, HALS, and an antioxidant.

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